


Fear the unknown

by aloserinthemaking



Series: Ducktales Crossover fics [1]
Category: DuckTales (Cartoon 2017), Gravity Falls
Genre: AU - they've never traveled to other dimensions, Also the pines twins are ducks because I said so, Alternate Universe, Dialogue Heavy, Gen, Honorary Duck Family Member Webby Vanderquack, I Don't Even Know, I Tried, I Wrote This Instead of Sleeping, I might include some other villains, I'm Bad At Tagging, I'm scared of this, Louie gets his own chapter so fight me, Might add more tags later, My First Fanfic, So do the others, Why Did I Write This?, and bill, and violet, but who cares right?, except Lena, honestly they all do, like when it's actually done, okay only the triplets and the twins, this is going to be interesting
Language: English
Status: In-Progress
Published: 2021-01-01
Updated: 2021-02-28
Packaged: 2021-03-11 03:28:42
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 8
Words: 3,258
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28488333
Author URL: https://archiveofourown.org/users/aloserinthemaking/pseuds/aloserinthemaking
Summary: They’re used to weird things happening. Relatives visiting from the past or the future? Happened before. Ghosts? Their butler is one. Magic? One of their closest friends is a sorceress. But one thing they’ve never even heard of is interdimensional travel, so what happens when twins from another universe are put into theirs?OrThere’s an interdimensional rift and ducktales and Gravity falls are shoved into the same universe.
Relationships: Dewey Duck & Huey Duck & Louie Duck, Dewey Duck & Huey Duck & Louie Duck & Webby Vanderquack, Dipper Pines & Mabel Pines
Series: Ducktales Crossover fics [1]
Series URL: https://archiveofourown.org/series/2089062
Comments: 10
Kudos: 30





	1. A what now?

**Author's Note:**

> So this is my first ever fanfiction and it's probably very bad just warning you. Also don't expect it to be updated often.

It was an average day for the McDuck family, Huey was going through books with Violet, Lena and Webby we’re chatting about their last adventure, Dewey wasn’t there, probably setting up some ‘epic’ stunt that would get him nearly killed, and Louie was sitting on the couch watching Ottoman Empire, when suddenly, Gyro appeared out of nowhere. 

“Mr McDuck! Oh wait, you’re just the nephews, and.. others.” he was very annoyed that their great uncle wasn’t there at the moment “Where’s your uncle” 

“Uncle Scrooge is out on a daring adventure too dangerous for us to come along” Webby said mysteriously. 

“Alright, who here is smart and has a slight chance at keeping up with my superior intellect”, before he even finished his sentence, everyone immediately pointed at Huey and Violet. “Okay then, the rest of you, just try to keep up”

“So, I was trying to make an interdimensional portal, when it exploded on me, as most things do. I thought everything was fine and I’d just see what went wrong and try again, when I found this lying around.” he held up a Mason Jar with a rainbow liquid in it. “This is, as you should know, an interdimensional rift. Unlike a portal, they cannot be closed. If this thing gets out of here it could expand and our entire universe would be in danger of imploding on itself” 

“So basically, keep the portal in the jar or we all die” Dewey stated everything Gyro had just explained in a much simpler sentence.

“Yes basically” 

“Cool, so, why exactly do we need to know that the universe is doomed or whatever?” Louie asked, not having paid any attention to the entire conversation.

“Because, I want you children to make sure it doesn’t break out”

“Wait wait wait, you’re trusting us of all people with this?!” Louie was not only shocked, but terrified, because he was extremely clumsy compared to his peers, making him the most likely to knock it down.

“Yes, don’t let me down” 

"Oh boy.."


	2. Oh boy...

**Notes for the Chapter:**

> YAY chapter two
> 
> I have no idea what I'm doing I'm sorry

It had been about a month since Gyro had given them the rift, and Louie had almost knocked it over at least a hundred times. He felt terrible about it, but he had zero coordination and couldn’t help it. 

“Louie be careful!” Huey yelled, as Louie ran into the cabinet holding the rift, but it was too late.

CRASH

The jar was broken, and the rift was expanding at an alarming rate. 

“We.. should probably tell Gyro about this” Huey suggested, more calm than he should’ve been.

“Ya think?!” Louie responded in a panic. They ran out of the room and into the corridor, when they got stopped by their uncle. 

“Why are you all running through the halls? And what’s with the hurry?” he asked, noticing the panic in their faces.

“No time to explain, need to get to Gyro’s lab” Dewey responded between breaths, and they were off.

Once they got there (which ended up taking a lot longer than they had expected) they started calling for him, only problem was, he wasn’t there.

“Dr. Gearloose is at a meeting with Mr. McDuck right now, but I can probably help you kids out!’ Fenton had confronted the kids after hearing the commotion. 

Huey started talking “Hey Fenton, this is going to sound crazy bu-” 

“We accidentally broke a jar and now there’s an interdimensional rift in our bedroom!” Louie finished, getting impatient.  
“I- uh, okay then. I have no idea how to help you sorry” he apologized, although still confused. 

Louie went back to the mansion to make sure everything was still under control, while Dewey and Webby went to see if they could find Gyro. Huey went back to the mansion with Louie, but immediately went looking through his Junior Woodchuck Guidebook to see if he could find anything on interdimensional rifts.

“There’s nothing on them in here! Or anywhere! I went on the website for the library and there’s nothing there either!” Huey was very frustrated, as he couldn’t find any information about interdimensional rifts anywhere. 

“Did you Google it?” Louie responded, making sure Huey did the most obvious way of researching.

“Of course I Googled it, are you dim?!” He responded, Louie realized that his older brothers anger issues were starting to show through.

“Alright, sorry I just was double checki-” 

BANG

“What was…”


	3. Who are I

**Notes for the Chapter:**

> no, the title of this chapter in not supposed to make grammatical sense

“What was that?” Huey asked, still laser focused on his JWG.

“Uh Huey you might want to see this…” 

“See what-” he looked over to where Louie was standing and saw two ducks laying on the floor on top of each other. One was a female with long hair and a large, pale blue sweater with a sun (which had sunglasses on, bothering Huey) on it, the other, a boy with short hair, a blue hat with a pine tree on it, an orange shirt and a dark blue vest. 

“Where are we?” the girl asked “I don’t remember this part of the Mystery Shack” 

“I don’t think we’re in the Mystery Shack” the boy responded, looking directly at Huey and Louie. 

“Ooh new friends! Hi, I’m Mabel, this is my twin brother Dipper, who are you guys??” The girl, Mabel rambled enthusiastically

“I’m Huey, this is my brother Louie” Huey introduced the two of them, Louie being terrified at the fact that there were people he didn’t know in his bedroom.

Mabel's face immediately lit up with excitement when she said “Are you guys twins too? Do you have a weird Gruncle you live with? Is this where you live? Do you have any other siblings? I don’t. How old are you? Me and Dipper are thirteen.” she asked a million questions. Louie was immediately reminded of Webby, and realized how well the two of them would get along.

“Sorta, we’re triplets, our brother Dewey is out right now. If ‘Gruncle’ means great uncle yes, if not I don’t know. Yes. Sorta, Webby is pretty much our sister as we live with her here, but she’s not blood related. Me, Dewey and Louie are eleven, and Webby is twelve.” Huey answered all her questions as he had done with Webby on the first day. 

“Huey, Louie we couldn’t fin- who are they?” Dewey and Webby had entered the room looking disappointed, until they saw the two ducks standing in the middle of the room.

“Hi, I’m Mabel! This is my twin brother Dipper. I’m going to assume from what these two have told me you’re Webby” She pointed to Webby “And, wait what was your name? Oh right, Bluey” She guessed based off of the name she vaguely remembered and the colour of his shirt. Dewey gave her an annoyed glare as he did with everyone who messed his name up.

“Actually it’s Dewey” he corrected

After a long while, Webby and Mabel connected, and very quickly became friends. Dewey was also friends with the two of them, although Mabel and Webby were more similar. 

At that same time, Huey and Dipper became friends, as the both of them were nerds who loved new information and solving mysteries. 

Louie was left alone. 

He wasn’t surprised, as this often happened. 

Huey had Fenton, Dewey had Launchpad, Louie had no one. 

Huey had Boyd, Dewey had that new girl, Gosalyn and Louie still had no one. 

He was used to being the odd one out. 

The only person Louie had really connected with was Lena, but she was always hanging out with Violet and Webby. 

So he left the room. This didn’t seem like a big deal to the only person who noticed, Dewey, as he assumed Louie was going to the washroom or getting a glass of water. 

He had been very wrong...


	4. I'm sorry

As his room was occupied, he decided to go to one of the guest bedrooms. He was tired and having a bit of a crisis. He needed time alone, which is hard enough when you live with three other kids and four other adults. Let alone when two new kids just appear out of nowhere. 

He had no idea what time it was when he finally woke up, his mind too distracted by the giant, one-eyed triangle floating in front of his bed.

“Uh- w-what the hell are you?”, he managed to stutter, terrified and confused. 

“Me? I’m Bill, Bill Cipher. And you’re Louie Duck.”, The triangle, Bill, responded. 

“Uh ye-yeah, how’d you know that?”

“I know everything! I'm all-knowing Bill!” 

“Really? How do you know everything? And how come I’ve never heard of you before?” 

“Well, you see…”, he answered every question Louie had, and asked him several as well. Louie was actually enjoying talking to Bill. He never really knew how to talk to people, but this guy seemed to understand how to make it easy on him. 

“Also, what are you doing in my bedroom?” he asked, making sure he wasn’t being kidnapped.

“I wanted to be friends! You don’t seem to have very many, after all,” he responded.

He was right. Louie didn’t have many friends. He wasn’t even sure he had any. Brothers don’t count as friends, after all. Many kids had told him that when he was young.

“O-oh, sure, we can be friends.”

Though still skeptical of him, Louie decided to trust this guy. He didn’t seem evi. He was actually pretty nice. Plus, he’d finally have a friend.

| The next day |

“Louie, wake up! We’re having pancakes for breakfast!!”, his brother yelled while bouncing on the bed. 

Breakfast? I didn’t even have dinner last night.

He looked around, vaguely remembering what had happened yesterday. He took a minute, but remembered Bill and the time they had talked. He wondered if it had all been a dream. He went downstairs to eat when he saw the twins they had just met there too. 

“Wait, are they living with us now?” he asked, not wanting to deal with another Huey and another Webby. 

“Until Gyro can get them back to their world, yes,” his great uncle responded.

“Louie how are you feeling? You slept for eighteen hours. We checked on you every few hours and you were always sleeping,” Donald asked his nephew, being concerned for the boy. 

“Oh, I’m okay, I was just a little tired and stressed from yesterday,” he responded without hesitation. The lie ran off his tongue with ease. He was good at it, ever since he was young. As soon as he had learned to talk, he learned to lie. 

And lies he didn’t know he would need…


	5. That's Curious

Huey had pretty much immediately become friends with Dipper. He was exactly like him. They both had a sort of book that held all the information they needed. They both went on adventures, not for the adrenaline, but rather for the mysteries that went with it. They both were huge nerds. They were perfect friends. Huey had lost his ability to notice things through being distracted by Dipper, though. Up until this day, he hadn’t realized how Louie was never around. How he didn’t want to talk to either of the twins. How he barely wanted to talk to anyone, even his brothers. 

He finally noticed.

“Wait a minute, where’s Louie been?” He asked one day, about a week after the twins had come through the rift. 

“I.. don’t know. When was the last time you saw him?” Dewey responded. 

“Uh.. actually, I think the last time I remember seeing him was the day after the twins came through the rift...” he started to panic. Where had his brother been this whole time? How had he not realized he was gone?

He decided to go to the last place he had seen him, in the guest bedroom down the hall.

“Hey Louie? Are you there?” he opened the creaky door. 

Louie was there, lying on the bed, but he wasn’t responding. 

“Louie?” he asked again, he went over, and saw he was… sleeping?

Why would he be sleeping at this time?, he wondered. He was starting to get worried, when he heard his brother say something. It was barely understandable, but he managed to catch a bit of it. 

“Really? Have wake up?” was all he heard, and from that he assumed he had said ‘Really? I have to wake up?’ 

“Not if you don’t want to, I guess.” 

“But wan stay talk to you” was the next few words he said, which Huey had no idea what it meant. “Fine,” was the last word he heard before his little brother woke up.

“Louie you alright? You were talking in your sleep. And where have you been for the past week?” 

“Oh, yeah I’m fine. I’ve been here, either playing on my phone or sleeping.” 

He was confused and concerned. Had Louie eaten? Had he gotten any water? Why did he need so much sleep? What was he talking about in his sleep? It seemed he was aware he was sleeping. 

What was happening to his little brother?


	6. He knows...?

**Notes for the Chapter:**

> Aye, look who's finally back with another chapter.

After about two weeks of his brothers nagging him, Louie finally decided he’d go with them on an adventure. 

They were going to Northern Ireland to find a hidden treasure from a hundred-some years ago. He only agreed to come along because of the nagging his brothers had given him.

The plane ride there had been long and bumpy due to Launchpad’s flight tendencies, and not one person had gotten a blink of sleep for the whole ten hours it had taken them.

Except, of course, Louie.

He’d fallen asleep about halfway through. 

He dreamt of what he usually did. Talking to Bill. Although this time felt different.

This time, rather than asking all about Louie, he asked a favour of him.

Louie though perplexed as to why accepted this favour. 

It was a mistake he couldn’t take back.

Dewey and Webby hadn’t seemed to notice him fall asleep, and if they did, they hadn’t seemed to care too much.

Huey on the other hand had noticed. 

He had noticed that his brother had managed to fall into a surprisingly deep sleep in a seemingly unsleepable environment.

He also noticed that his brothers’ eyes would occasionally flicker open to reveal yellow eyes with cat-like pupils.

The first time it had happened he thought it was just his eyes playing tricks on him, which happened often with the bumps of the plane and the strange angles of the sun. After seeing the same thing several times though, he realized that it wasn’t just him, or the light. 

Something was up, and he was going to figure out what.

\-------------------------------------------------  
Time Skip (because I decided so)  
\--------------------------------------------------

He didn’t know what had happened, because when he woke up he was on the airplane, but this time everyone was not only yelling at each other but also really mad at him.

His immediate older brother was the maddest, and his eldest brother was the least mad surprisingly. 

He didn’t understand why, but Dewey suddenly started yelling at him.

“Oh, look who’s finally awake!” he exclaimed, anger lacing each word.

He tried asking what he did, only to get the response of “you know what you did” 

His other brother, Huey, was much different about it. He explained what happened, but also explained some little things he had noticed. Like how his eyes looked odd, and his voice seemed off. He only mentioned it to Louie, fearing the theories Webby could come up with, and not knowing how he’d explain it to the adults. 

Louie was scared because of it.

He knew the eyes he’d described.

He knew where it all had come from.

And to think he’d even thought to put trust in this guy?

That was when he knew he needed to get him out of his brain. He just didn’t quite know how.

**Notes for the Chapter:**

> Fun fact: I'm starting another crossover, which I might start posting eventually.
> 
> Not telling what it is though, but I'll give you hints for each chapter until it's uploaded or I just feel like telling you. Feel free to guess. I'll tell you if you're right or wrong.
> 
> Your hint, for now, is: Jitsu
> 
> That's literally your entire hint
> 
> I know I'm making it really difficult.
> 
> That's the point though.


	7. An unlikely friend

**Notes for the Chapter:**

> Guess who's back 
> 
> Back again
> 
> Sorry, this chapter is kinda really super bad but the story gets juicier later I promise.

At first, he couldn’t figure out who to go to. Scrooge supposedly knew nothing about “dream demons” according to Webby, his brothers and Webby would make him tell Scrooge, and his Uncle Donald and mom would both probably freak. Plus, he had a feeling this guy wasn’t from their dimension. The only other people he could go to were the new kids, Dipper and Mabel. 

And so he asked them.

“Hey, Dipper, Mabel,” He cautiously approached them hoping to get some answers. He got a hum in response and just hoped that they had heard him. 

“There’s this triangle dude in my head and I have a feeling he’s not from our dimension. Do you know anything about him?” Louie asked, trying to be straight to the point.   
He saw Dipper turn around looking slightly terrified and Mabel look like she would die if she got even the slightest other scare. He didn’t quite understand what it meant, but he knew that Bill wasn’t good news. 

“Well, you see here..” Dipper started explaining, sounding nervous yet trying to stay calm. 

He then explained the entire situation with Bill, how he’d taken over Dipper’s body to steal a journal, nearly destroyed the entire world with a disaster called “weirdmageddon” etc, etc. 

“So how do I get him out of my head?” Louie asked the question he’d come to them for. 

“We don’t know, usually he can come and go in everyone’s heads, so sometimes he there other times he’s not. I’m pretty sure if you just ignore him he’ll be out of your head. The problem is, since he’s in your world, terrible terrible things could happen.”

“And with that rift, he might be able to get the guys from his dimension here!” Mabel exclaimed. She seemed twenty times as nervous as Dipper, although Louie had a feeling he was just better at hiding it. 

“So what do we do?” Louie asked, not knowing where to go from there. 

“We wait obviously”

They didn’t have to wait long though, as when Louie was about to get up and leave, Bill appeared out of thin air and started talking to them. 

“Hey, Pine Tree, what’s up? I see you’ve figured out I’m in this kid’s dimension now. Pretty cool am I right?” He started joking around, clearly familiar with Dipper.

“No that’s not ‘cool’ I’m going to need you to leave this dimension before you destroy it like you almost did with ours” Dipper was angry now. There was no mistaking it. 

“No can do kiddo, I have to have some fun before I go back to that boring old place.” 

Dipper tried to tackle him multiple times and failed every time before he gave up.

“I will find you and send you back. I will.” 

“We’ll see about that kiddo” 

He was gone. 

“So, where do you think he went?” Louie asked, clearly wanting to stop him from destroying his home. 

“No clue, he could be anywhere. Inside anyone’s head. At any time.”

He asked about twenty different questions before they decided it would be best to go search for him. So they went and gathered everyone and left.

**Notes for the Chapter:**

> Your lovely clue for this week is: 
> 
> It was on Nickelodeon, somewhere, at some point in time. 
> 
> That's it that's your clue.
> 
> Like it didn't have to be on Nickelodeon where you're from or where I'm from as long as it was on it somewhere. 
> 
> Could've been there in Antarctica for all I care.
> 
> That's your hint. 
> 
> I'm really mean I'm sorry.


	8. real quick authors note (will be deleted when new chapter is up)

Hello hello, friends. I'm kinda having writers' block rn, along with the fact that I have a ton of homework and have decided for my next like, four fics I have in progress I should probably write them, edit them and then have a somewhat steady uploading schedule. So, basically, this is going to be on hiatus until my brain can come up with ideas for it. I might start uploading another fic during the hiatus depending on how long it lasts. Cool? Cool. 

Hope you're having a good day :)


End file.
